Magnetizable wedge for dynamo-electric machines.



R. E. HELLMUND.

MAGNBTIZABLE WEDGE FOR DYNAMO ELECTRIC MACHINES.

APPLIOATIOH FILED AUG. 2, 1909.

Patented Apr. 30, 1912.

INVENTOR fiu doff f. fiel lmunal WITNESSES ATT'ORNEY STATES PATENT OFFICE.

mmoLr E. HELLMUNlD, F rrrrsnumih, PENNSYLVANIA, ASSIGNOR ro wnsrmo- HOUSE ELECTRIC AND manurac'runmq cp uranr, A conronarron or PENN- SYLVANIA.

MAGNETIZABLE WEDGE FOR DYNAMO-ELECTRIC MACHINES.

Patented Apr. 30, 1912.

To all 107L077), it may concern:

Be itknown that I, RUDOLF E. HELL- MrNn. a subject of the Emperor of Germany, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Magnetizable edges for Dynamo-Electric Machines, of which the following is a specification.

My invention relates to dynamo-electric machines having magnetizable core members provided with open slots for the reception of coils and it has for its object to provide a magnetizable wedge which shall be simple in construction and adapted to securely hold the coils in the slots in opposition to centrifugal and magnetic forces tending to (llSPlRCt' them and also substantially produce the operating characteristics of partially-rloscd-slot machines.

The lllfl llltlllztllile wedge of my present invention is particularly adapted for use 'with induction motors having wound secondaries that are operated at high speeds and the core members of which are provided with a large number of relatively small slots for the reception of the windings. It is evident to those skilled in the art that it is particularly ditlir-ult to provide magnetizahle wedges which will successfully perform their functions when made in very small sizes and uti ized with induction motors having very small air gaps, since the magnetic fort-rs tending to displace the wedges are very great.

.iccording to my present invention, I excnd the wedges beyond the ends of the core slots and w ind a number of convolutions of steel hand wire upon the projecting ends for the purpose of holding them securely in po sition.

Figure l of the accompanying drawings is a sectional elevation of a portion of the core member of a dynumo-clcrt ric machine which is equipped with my invention. Fig. 2 is a sectional elevation, at right angle to that of Fig. 1, showing a single slot. the coil being shown in llwslll'lll. Fig. 3 is a detail view of the wedge shown in Fig; l and 2. and t Figs. 4, 5 tllltl ii are views Corr spoiuling to Fig. 2 but showing modified wedge struc turcs which rudiody u." inventi n.

ltefcrrin; to Figs. l, 2 and i of the drawlugs, a lilagnotizn ilc orr !ttt"lii "'l l of a dyi Application. filed August 2, 1909. Serial No. 510.839.

narn'o-electric machine, having radial coreslots 2, isprovided with a'winding 3 which s partially located in the slots 2 and is held In" position by magneti'zable ayedges The slots are of the open type-fiend their side walls are provided with grooves 5 to receive the wedges 4. Each of the wedges is composed of a central strip 6 having longitudinal slots 7 cut in it and side pieces 8 which are integral with the central strip and form lateral projections. The central strip corresponds in length to the slots 2, but the projections 8 extend materially beyond the ends of the central strip so that they are adapted to receive a plurality of convolutions 9 of band wire for the purpose of holding the wedges securely in position after they have been assembled in the core slots, as shown in Fig. 1 of the drawings. If the longitudinal slots 7 were omitted, the harmful magnetic flux across the slots would be greatly increased, whereas, when they are present, the operating characteristics of a partially-closed-slot machine are approximated.

The hand wire may be replaced by rings, within the scope of my invention.

Referring to Figs. 4, 5 and 6 of the drawings, the wedge shown in Fig. 4 is similar to that shown in Fig. 2 except-that the cross sectional form is slightly modified. In Fig. 6, the ma netizable wedge is similar to that of Fig. 4, nt an angle strip 10 of non-magnetic material is located between the projection 8 of the wedge and the groove 5. In Fig. 5, a magnetizable strip 11 is riveted to a mom magnetizable strip 12 which constitutes the usual wedge for holding the coils in the slot while the strip 11 serves to improve the characteristics of the machine. The ends of the magnetizahle portions of the wedges shown in Figs. 4, 5 and 6 are preferably extended to correspond to the wedge shown in Fig. 1.

I desire that variations in size and structure which do not depart from the spirit of my invention shall be included within its v cope.

I claim as my invention:

1. The combination with a core member of a dynamo-clcrt'ric machine having core slots for the rcct-pti ui of coils. of magnoliai alilc wedges located in the op nings oi' the slots and havino laterally projecting side pieces of greater length than the body portions that project beyond the ends of the core slot, and bands for holding the wedges in position.

2. In a dynamo-electric machine, the combination with a magnetizable core member having a plurality of coil-containing slots, of Wedges for holding the coils in position each of which comprises a ma etizable strip having side pieces the ends 0 which project beyond the body portions and the ends of the core slots, and bands surrounding the pro ecting ends of the wedges for preventing their displacement. j

3. In a dynamo-electric machine, the combination with a ma etizable core member having teeth which orm slots for the reception of coils and are provided with grooves in their sides and adjacent to their free ends, of wedges for holding the coils in position in the slots each of which comprises a magnetizable strip having centrally located longitudinal slots and side pieces projecting beyond the core member, and a plurality of convolutions of b and wire surrounding the projecting ends of the side pieces for preventing their displacement.

In testimony whereof, I have hereunto subscribed my name this 28th day of July,

RUDOLF E. HELLMUND. Witnewes:

(Immune W. MoGmm, R. J. DEARBORN. 

